The invention relates to spherical bearings utilizing overlay cast bearing shells and the method of forming said bearing shells. Spherical bearings which have had very specialized use in commercial designs, provide a rotational connection joint between two elements. An example would be a piston rod which rotates in multiple planes with a reciprocating piston which moves linearly. A spherical bearing of the type involved in the present invention is taught in FIG. 5 of applicant's pending application Ser. No. 512,120, entitled Axial Cylinder Internal Combustion Engine. Overlay spherical bearings in the prior art have generally been formed by filling the bearing housing with cast bearing metal, and then machining away the bearing overlay material to form the finished spherical bearing surface therein. This of course involves substantial machining on the inside surface of the bearing shell including accurate shaped lubrication grooves in the finished spherical bearing surface.
The present invention substantially reduces these machining requirements since the spherical bearing surface and its attendant lubrication grooves are provided at the time of the casting of the bearing overlay material.